Safety-clutch for elevators



.(No Model.) 2 Shgets-She'et 1.

-. .ALBRO.

v SAFETY GH POR'BLEVATORS.

No, 501,396. Patented July 11,1893.

2 Sheets-Sheet 2.

(No Model.)

0'. E. ALBRO. SAFETY CLUTCH FORELEVATORS.

Patented July 11, 1893.

UNITED STATES PATENT OFFICE.

CHARLES E. ALBRO, OF PHILADELPHIA, PENNSYLVANIA.

SAFETY-C LUTC H FO R ELEVATO RS.

SPECIFICATION forming part of Letters Patent No. 501,396, dated July 11, 1893.

Application filed January 26, 1893. Serial No. 459,385- (No model.)

To all whom it may concern:

Be it known that I, CHARLES E. ALBRO, a citizen of the United States, and a resident of Philadelphia, Pennsylvania, have invented certain Improvements in Safety-Clutches for Elevators, of which the following is a specifi-. cation.

My invention relates to certain improvements in the construction and operation of safety clutches for elevators, as more fully described hereinafter, reference being had to the accompanying drawings, in which.

Figure 1, is a perspective view of a portion of the frame of an elevator, and the guideways therefor. Fig. 2, is an elevation of the same. Fig. 3, is a sectional view on the line 1-2, Fig. 2. Fig. 4, is a similar view illustrating the parts in a different position; and

Fig. 5, is a perspective View of one of the clutching blocks.

My invention consists of an improved construction of devices for clutching the guiding strip on each side of the elevator shaft when, by reason of the breakage of the hoisting rope, the elevator, in falling, is clamped to the guiding strips and its downward movement arrested.

In the accompanying drawings A, A, represent the guiding strips placed on each side of the elevator well, and adapted to such strips are the ordinary guides at placed usually at the top and bottom of the elevator frame work; the top guides only being shown in the present instance.

The upper cross bar B, is slotted for the reception of a sliding bar 0, to the upper end of which is secured the hoisting rope D, and its lower end isin the form of a box 0, through which passes a leaf spring E, the opposite ends of which are attached at e e to the under side of the cross bar. This spring is not strong enough to resist the weight of the car and load and usually the parts assume the positions illustrated in Figs-1, 2 and 3, with the upper part of the block or box 0 fittingsnugly against the under side of the cross bar B. On either side of the bar B are rock shafts G adapted at their opposite ends, near the extreme ends of the bar B or on the vertical posts on each side of the elevator frame, to bearings g, and carrying at their extreme ends clutching blocks H of a construction more clearly illustrated in the perspective View, Fig. 5, these blocks H being secured in suitable position to the shaft G by set screws 1 and having toothed or serrated faces in proximity to the guide strips A. At a central point on each shaft G is secured a slotted arm or lever K, in the slot is of which travels a pin Z secured to an arm L projecting from the box 0, and the relative position of the parts being such that when in normal position, as shown in Fig. 3, the pins Z will be at or near the inner ends of the slots is.

If the hoisting ropeD of the elevator should break all tension on the bar 0 is removed and it will then be acted upon by the leaf spring E, causing its downward movement to or about the position shown in Fig. 4., the pins Z traversing the slots is in the armsK and effecting the movement of the rock shaft G in the direction of the arrow Fig. 4, and the clutching blocks at the opposite ends of the shaft G being, by this movement, brought into contact with the guiding strips A and arresting the downward movement of the car. These clutching blocks are so constructed that the first point of contact is on that portion of the clutching face nearest to the shaft G, but as the blocks are brought into contact with the guiding strips Athe catching of the first tooth will cause the blocks to rotate more and more until, if the elevator be heavily loaded, the teeth at that point of the clutching face farthest from the shaft will sink deeply into the guiding strips A and hold the elevator firmly.

It will be noticed, on reference to Fig. 5, that the teeth h of the clutching block are in two rows and staggered so that the points of the teeth of the upper row willbe intermediate of those in the lower row and a quicker clutching face may be had with teeth of the same size than if the teeth extended directly across the periphery of the block or more than two rows may be used as shown by dotted lines in Fig. 5. Another advantage gained by this staggering of the teeth is that any great mutilation of the ash guiding strip Ais prevented, as distinguished from the mutilating effect of teeth of the same size extending entirely across the face of the block.

Having thus described my invention, I claim and desire to secure by Letters Patent- The combination of the elevator frame, the

1o ing blocks having serrated edges carried by said rock shaft and adapted to engage with guiding strips in the elevator well, substantially as specified.

In testimony whereof I have signed my name to this specification in the presence of I 5 two subscribing witnesses.

CHARLES E. ALBRO. Witnesses:

.INO. E. PARKER, JOSEPH I-I. KLEIN. 

